package com.sun.filesigndemo.common.security.Realm;


import com.sun.filesigndemo.bussiness.mapper.UserMapper;
import com.sun.filesigndemo.common.entity.User;
import com.sun.filesigndemo.common.security.UserUtils;
import com.sun.filesigndemo.common.security.session.SessionDAO;
import com.sun.filesigndemo.common.servlet.ValidateCodeServlet;
import com.sun.filesigndemo.common.utils.Encodes;
import org.apache.shiro.SecurityUtils;
import org.apache.shiro.authc.*;
import org.apache.shiro.authc.credential.HashedCredentialsMatcher;
import org.apache.shiro.authz.AuthorizationInfo;
import org.apache.shiro.authz.Permission;
import org.apache.shiro.authz.SimpleAuthorizationInfo;
import org.apache.shiro.realm.AuthorizingRealm;
import org.apache.shiro.session.Session;
import org.apache.shiro.subject.PrincipalCollection;
import org.apache.shiro.util.ByteSource;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.stereotype.Service;
import tk.mybatis.mapper.entity.Example;

import javax.annotation.PostConstruct;
import java.util.Collection;
import java.util.List;

import com.sun.filesigndemo.common.security.Token.UsernamePasswordToken;

/**
 * 系统安全认证实现类
 * @author Winkey
 * @version 2017-11-06
 */
@Service
public class SystemAuthorizingRealm extends AuthorizingRealm {

	private Logger logger = LoggerFactory.getLogger(getClass());
	
	public static final String HASH_ALGORITHM = "SHA-1";
	public static final int HASH_INTERATIONS = 1024;
	public static final int SALT_SIZE = 8;
	
	@Value("${app.singleLogin}")
	Boolean singleLogin;
	@Autowired
	private SessionDAO sessionDao;
	@Autowired
	UserMapper userMapper;
	
	public SystemAuthorizingRealm() {
		this.setCachingEnabled(false);
	}

	@Override
    public Class getAuthenticationTokenClass() {
        return UsernamePasswordToken.class;
    }
	
	/**
	 * 认证回调函数, 登录时调用
	 */
	@Override
	protected AuthenticationInfo doGetAuthenticationInfo(AuthenticationToken authcToken) {
		UsernamePasswordToken token = (UsernamePasswordToken) authcToken;
		
		// 校验登录验证码
		if (UserUtils.isValidateCodeLogin(token.getUsername(), false, false)){
			Session session = UserUtils.getSession();
			String code = (String)session.getAttribute(ValidateCodeServlet.VALIDATE_CODE);
			if (token.getCaptcha() == null || !token.getCaptcha().toUpperCase().equals(code)){
				throw new AuthenticationException("msg:验证码错误, 请重试.");
			}
		}

		if (token.getUsername() == null) {
		    return null;
        }


		User user= checkUser(token.getUsername());

		if (user != null) {
			byte[] salt = Encodes.decodeHex(user.getPwd().substring(0,16));
			return new SimpleAuthenticationInfo(new Principal(user, token.isMobileLogin()), 
					user.getPwd().substring(16), ByteSource.Util.bytes(salt), getName());

		} else {
			return null;
		}
	}
	
	/**
	 * 获取权限授权信息，如果缓存中存在，则直接从缓存中获取，否则就重新获取， 登录成功后调用
	 */
	protected AuthorizationInfo getAuthorizationInfo(PrincipalCollection principals) {
		if (principals == null) {
            return null;
        }
		
        AuthorizationInfo info = null;

        info = (AuthorizationInfo)UserUtils.getCache(UserUtils.CACHE_AUTH_INFO);

        if (info == null) {
            info = doGetAuthorizationInfo(principals);
            if (info != null) {
            	UserUtils.putCache(UserUtils.CACHE_AUTH_INFO, info);
            }
        }

        return info;
	}

	/**
	 * 授权查询回调函数, 进行鉴权但缓存中无用户的授权信息时调用
	 */
	@Override
	protected AuthorizationInfo doGetAuthorizationInfo(PrincipalCollection principals) {
		Principal principal = (Principal) getAvailablePrincipal(principals);
		// 获取当前已登录的用户
		if (singleLogin){
			Collection<Session> sessions = sessionDao.getActiveSessions(true, principal, UserUtils.getSession());
			if (sessions.size() > 0){
				// 如果是登录进来的，则踢出已在线用户
				if (SecurityUtils.getSubject().isAuthenticated()){
					for (Session session : sessions){
						sessionDao.delete(session);
					}
				}
				// 记住我进来的，并且当前用户已登录，则退出当前用户提示信息。
				else{
					SecurityUtils.getSubject().logout();
					throw new AuthenticationException("msg:账号已在其它地方登录，请重新登录。");
				}
			}
		}

		User user= checkUser(principal.getLoginName());
		if (user != null) {
			SimpleAuthorizationInfo info = new SimpleAuthorizationInfo();
			// 补充获取用户权限逻辑
//			List<String> list= new ArrayList<>();
//			for (String menu : list){
//				if (StringUtils.isNotBlank(menu)){
//					// 添加基于Permission的权限信息
//					for (String permission : StringUtils.split(menu,",")){
//						info.addStringPermission(permission);
//					}
//				}
//			}

			// 添加用户角色信息
//			List<String>  roleList= new ArrayList<>();
//			roleList.add("admin");
//			for (String role : roleList){
//				info.addRole(role);
//			}
			// 更新登录IP和时间
			//getSystemService().updateUserLoginInfo(user);
			// 记录登录日志
			//LogUtils.saveLog(Servlets.getRequest(), "系统登录");
			info.addStringPermission("user");
			if (user.getIsAdmin()) {
				info.addStringPermission("admin");
			}
			return info;
		} else {
			return null;
		}
	}
	
	@Override
	protected void checkPermission(Permission permission, AuthorizationInfo info) {
		authorizationValidate(permission);
		super.checkPermission(permission, info);
	}
	
	@Override
	protected boolean[] isPermitted(List<Permission> permissions, AuthorizationInfo info) {
		if (permissions != null && !permissions.isEmpty()) {
            for (Permission permission : permissions) {
        		authorizationValidate(permission);
            }
        }
		return super.isPermitted(permissions, info);
	}
	
	@Override
	public boolean isPermitted(PrincipalCollection principals, Permission permission) {
		authorizationValidate(permission);
		return super.isPermitted(principals, permission);
	}
	
	@Override
	protected boolean isPermittedAll(Collection<Permission> permissions, AuthorizationInfo info) {
		if (permissions != null && !permissions.isEmpty()) {
            for (Permission permission : permissions) {
            	authorizationValidate(permission);
            }
        }
		return super.isPermittedAll(permissions, info);
	}
	
	/**
	 * 授权验证方法
	 * @param permission
	 */
	private void authorizationValidate(Permission permission){
		// 模块授权预留接口
	}
	
	/**
	 * 设定密码校验的Hash算法与迭代次数
	 */
	@PostConstruct
	public void initCredentialsMatcher() {
		HashedCredentialsMatcher matcher = new HashedCredentialsMatcher(HASH_ALGORITHM);
		matcher.setHashIterations(HASH_INTERATIONS);
		setCredentialsMatcher(matcher);
	}
	
//	/**
//	 * 清空用户关联权限认证，待下次使用时重新加载
//	 */
//	public void clearCachedAuthorizationInfo(Principal principal) {
//		SimplePrincipalCollection principals = new SimplePrincipalCollection(principal, getName());
//		clearCachedAuthorizationInfo(principals);
//	}

	/**
	 * 清空所有关联认证
	 * @Deprecated 不需要清空，授权缓存保存到session中
	 */
	@Deprecated
	public void clearAllCachedAuthorizationInfo() {
//		Cache<Object, AuthorizationInfo> cache = getAuthorizationCache();
//		if (cache != null) {
//			for (Object key : cache.keys()) {
//				cache.remove(key);
//			}
//		}
	}

	private User checkUser(String username) {

		// 校验用户名密码
		User user= new User();

		Example example= new Example(User.class);
		Example.Criteria criteria= example.createCriteria();
		criteria.andEqualTo("phone", username);
		Example.Criteria criteria2= example.createCriteria();
		criteria2.andEqualTo("name", username);
		example.or(criteria2);
		List<User> userList = userMapper.selectByExample(example);
		if (userList == null || userList.size() ==0)
			return null;
		return userList.get(0);
	}
}
